• International conference on construction engineering and project management
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• 2009.05a
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• pp.457-463
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• 2009

The earthwork is essential procedure for all civil engineering projects. Because of its importance in terms of cost and time, it should be managed effectively. In light of this, The Intelligent Excavating System (IES) research consortium has established to improve the productivity, quality and safety of current excavating/earthwork system by the Ministry of Land, Transportation and Maritime Affairs (MLTM) of Korea. This paper summarizes ongoing research aimed at development knowledge and presents a framework of task planning and visualization system for IES. The task planning and visualization system consists of three functions. 1) Using digital terrain model which created by 3D laser scanner, the system can divide it and generates global/local work area so that the excavator can work through the area. 2) In order to operate and/or control the excavator, the system exports the location, paths of boom, arm and bucket data of the excavator to control center. 3) The task planning system is visualized on the computer programming aided-graphic interface which simulates the planned work processes and eventually assists the operator for the control of the excavator. The case study which we have performed, demonstrates the effectiveness of the proposed system.

• Korean Journal of Construction Engineering and Management
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• v.6 no.5 s.27
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• pp.89-101
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• 2005

The early phase of construction projects, communication among the related participants has great influence on the further transaction of the projects. However, important decision making are made by the experience of the field managers in practice without the method for systematic analysis. For example, in building construction project, selection process for construction method has been executed by decision making of some architects dependent on their experience. As a result, there have been frequent construction method alterations during the construction process and delay of duration, addition of cost, etc have followed accordingly. The main reasons of such a mal-functional transaction are due to the absent of the reasonal procedure of decision making reflecting the characteristics of construction project. Therefore, there is a need for an supporting tool and production design for the selection of rational construction method. The objective of this study is to propose production design process and decision making model in relation to various influent factors at the early phase of construction projects. To achieve these objectives, this study 1)analyzes the prior theory about production design, 2)we have studied about selection process for optimal construction method through constraint analysis in structural works, 3)performs a case study to embody the problems of the production design, and 4)proposes a cooperative committee model for supporting production design by analyzing the results of case study and interviewing experts. It is anticipated that the effective tool of proposed model would be able to improve communication among the related participants and systematically accumulate data that might be used in similar construction projects.

• Land and Housing Review
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• v.2 no.2
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• pp.101-109
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• 2011

Recently, the construction of U-City or of U-City service (U-service) in many kinds of urban development projects becomes the general trend. However, as the construction of U-city comes into the spotlight like the trend of the times, various service constructions are being indiscreetly implemented since it's processed focusing on local specialized projects or local landmark project by a local autonomous entity or an institute in charge being off the original purpose of the improvement of living quality of residents and the efficiency of urban management, which causes a number of problems on the process, maintenance, operation and management of those projects. Therefore, this study is to derive the standard pattern of U-service construction through the analysis of patterns and numbers of U-service and problems during the process of construction in domestic U-City construction case district, and is aimed to suggest the reasonable direction of service construction based on this. 11 projects areas in which data related to U-service are available among U-City construction project areas were selected for the subjects of this study, and it's standardized with 228 detailed unit services that were suggested by U-Eco City R&D and with 11 service domains that are regulated in "the Act of ubiquitous city construction etc.", and it is limited to services that were suggested in U-City case area of which design was completed by July, 2010 based on this. The actual state of various U-service construction is analyzed through case studies as well as reviews on the legal and theoretical concept and the method of pattern classification of U-service, the plan for the standardization (pattern classification) of U-service and the plan for the construction body of service and to share the costs are suggested as the plan to construct reasonable U-service based on this for the method and the procedure of this study For the method to construct U-service, the plan to classify the pattern of U-service into the basic service and additional service is suggested, and whether it has the publicity, whether urban infrastructure is included, whether utilities are included, the body of realization, the recipients, the urgency, the importance and the spreading, etc. are suggested for the index to determine the pattern of service. The method to get the executor of a project to construct the basic service, the method to get the executor of a project to construct the most basic service among the group classification of service and to get a private entity and a local autonomous entity to perform additional service in the future, and the method to construct the whole service and to distribute the construction costs were suggested, and the first one that determines the body of construction after dividing U-service into the basic service and the additional service was evaluated to be the most reasonable one. And the plan to solve the problem that the excessive construction costs of U-service are shifted onto the executor of a project through benefit principle, balanced distribution principle and consultation and mediation between the interested parties was suggested for the criteria to share the costs.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.369-376
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• 2018

The majority of construction projects, from the initiation phase to the project completion and operation phase, are influenced by various types of corruption. Iran, as a developing country, has been suffering from this issue in bidding, tendering procedure, contracts etc. Therefore, due to the importance of this issue, this study attempted to identify the causes of corruption and evaluate the most significant factors in the construction projects in Iran. To this aim, an intensive literature review was performed to investigate the various types of corruption and identify the potential factors causing corruption in construction projects. The questionnaire survey was designed, considering twelve forms of corruption, including 77 causes of corruption in construction projects in Iran. Out of 220 distributed questionnaires, 188 were returned by the participants. The valid collected data sets were analyzed and then Exploratory Factor Analysis was applied. It was discovered that "Inappropriate power-sharing," "Lack of obligation for human resources to properly use resources and abide by the rules and regulations" and "Lack of any monitoring of the government's performance" are the most significant factors. Findings from the study would be valuable for the construction projects authorities and academia in order to combat corruption in the construction projects.

• Journal of Korean Society of Disaster and Security
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• v.14 no.3
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• pp.39-49
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• 2021

According to the recent "Status of Industrial Accidents at the End of December 2020" released by the Ministry of Employment and Labor, each industry is subject to industrial accidents. The number of accident deaths by construction industry, accident deaths by accident type fell, and accident deaths by workplace size were 5 to 49, indicating that most accident deaths occurred due to falling accidents at small construction sites. Therefore, urban living houses are small construction sites, and the probability of falling accidents is very high. Fall simulation training for disaster occurrence is conducted mainly by large construction ordering organizations in the public sector, and it is the first case in Korea that a housing construction company has conducted at a small construction site. This study analyzed and presented the definition, construction characteristics, and safety management status of urban living houses, and developed and spread an emergency relief procedure manual in the event of a fall accident to minimize deaths.

• Computers and Concrete
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• v.33 no.5
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• pp.535-544
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• 2024

In the rapidly advancing landscape of computer vision (CV) technology, there is a burgeoning interest in its integration with the construction industry. Camera calibration is the process of deriving intrinsic and extrinsic parameters that affect when the coordinates of the 3D real world are projected onto the 2D plane, where the intrinsic parameters are internal factors of the camera, and extrinsic parameters are external factors such as the position and rotation of the camera. Camera pose estimation or extrinsic calibration, which estimates extrinsic parameters, is essential information for CV application at construction since it can be used for indoor navigation of construction robots and field monitoring by restoring depth information. Traditionally, camera pose estimation methods for cameras relied on target objects such as markers or patterns. However, these methods, which are marker- or pattern-based, are often time-consuming due to the requirement of installing a target object for estimation. As a solution to this challenge, this study introduces a novel framework that facilitates camera pose estimation using standardized materials found commonly in construction sites, such as concrete forms. The proposed framework obtains 3D real-world coordinates by referring to construction materials with certain specifications, extracts the 2D coordinates of the corresponding image plane through keypoint detection, and derives the camera's coordinate through the perspective-n-point (PnP) method which derives the extrinsic parameters by matching 3D and 2D coordinate pairs. This framework presents a substantial advancement as it streamlines the extrinsic calibration process, thereby potentially enhancing the efficiency of CV technology application and data collection at construction sites. This approach holds promise for expediting and optimizing various construction-related tasks by automating and simplifying the calibration procedure.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.131-136
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• 2006

In constructing projects, there exist various kinds of work interferences, which cause a delay of the outset and completion of planned schedule because of some attributions, such as variability, uncertainty and complexity. and so schedule delay has been treated as a natural phenomenon. To reduce or prevent the schedule delay, a constant confirmation of schedule delay and a preparation of counter plans for finding out the cause structure of schedule delay should have been done. However, all this time the research has been mostly done on the calculation method or claim cases of schedule delay. Moreover, the analysis method did not consider the trait, which cause the schedule delay, in constructing projects. This paper restricts the range of the cause analysis of schedule delay to the field of site management in the projects and divides the cause structure of schedule delay into the cause objects and cause attributes of schedule delay according to the input elements. The system of classifying causes of schedule delay is examined by interviews with experts and questionnaire. Additionally, this paper analyzes the attributes of cause attributes and cause subjects and presents the analysis method and procedure of schedule delay with the application of VSM.

• Korean Journal of Construction Engineering and Management
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• v.9 no.5
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• pp.168-175
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• 2008

Project risk factors are major triggers in cost performance in construction projects. Both owners and contractors are highly concerned in managing their risks in earlier times. As such, it is needed to provide a robust risk evaluation methodology in identifying and assessing the potential risks before project execution. In previous research, risk identification was conducted only in specific phases, i. e., design, procurement, construction. Therefore, the comprehensive approach in risk management was limited and their quantifying method was not well-defined. Since the benefit of planning in earlier times are maximized compared to later times, the risk management should be implemented in earlier planning stage. This study provide a new risk evaluation method by incorporating previous research and extensive literature review. By quantifying each risk factor from an extensive industry survey, the proposed tool can enhance the reliability of each factor weight and also the weights are categorized from a various perspectives, i.e., owners, contractors, lager-scale company, smaller-scale company, building projects. The proposed tool can be also useful in deciding on whether to proceed a particular project and How much the project contingency would be set aside in project execution. The study findings can also expedite the risk management procedure in a more systematic approach.

• International Journal of Highway Engineering
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• v.20 no.1
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• pp.1-8
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• 2018

PURPOSES : Case studies of an asphalt-overlay project with a performance-based contract method were conducted on a national highway in Korea to evaluate the effect of the method on asphalt pavement maintenance. This study evaluated the procedure of the performance-based contract method. METHODS : In this study, an asphalt-pavement maintenance project for a national highway was assessed with a performance-based contract to investigate the advantage of the new contract procedures. This is the first trial applying the performance-based contract to a pavement-rehabilitation project in Korea. In the four case studies, the warranty period of the performance-based contract was designed for seven years. The research team monitored the construction site to compare the normal contract method with the performance-based contract method. The case studies' project sites were investigated after the end of the construction. RESULTS : Based on the limited case studies, the performance-based contract method could extend the service life of the asphalt pavement and reduce the pavement-maintenance budget because the quality control was well managed by the contractors. However, a few construction laws would be necessary to apply the performance-based contract method in the future. CONCLUSIONS : Using the performance-based contract, the construction company made great efforts to guarantee the warranty period and to apply the optimal maintenance method, based on the pavement distress condition. The contractor and the agency would need to understand the new performance-based contract system for it to be activated. Therefore, a proper education program for the performance-based contract system would be needed to educate the stakeholders regarding the procedures and their effects on the pavement management and maintenance.

• International Journal of Highway Engineering
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• v.15 no.2
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• pp.1-9
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• 2013

PURPOSES : The PMS(Pavement Management System) has been utilized in order to efficiently allocate the limited budget for the maintenance of national highway system. In the PMS of national highway, surface pavement condition is evaluated by using the VI (Visual Index). However, the VI is determined only by considering the cracking rate (%) and rut depth (mm), which is not reflecting the IRI (International Roughness Index) that is known as an important factor of pavement performance. In this study, the NHPCI (National Highway Pavement Condition Index) which includes the cracking rate (%), rut depth (mm), and IRI (m/km) is suggested for determining the rehabilitation methods group. METHODS : First, the rehabilitation methods performed between 2008 and 2010 on the national highway is classified and then, NHPCI is determined for each rehabilitation method. Next, the NHPCI for each rehabilitation method is grouped through the interval estimation of the population mean and T-test analysis. RESULTS : According to NHPCI range, the rehabilitation methods are divided into four categories: Not Required, Preventive Maintenance, Overlay Treatment (with or without cutting), and Full-scale Treatment (i.e., reconstruction). CONCLUSIONS : Based on this study, it is recommended that the appropriate NHPCI range should be determined through the combination of the rehabilitation categories and Decision Procedure of Pavement Distress Condition Visual Index.